Multilayered body for photolithographic patterning

ABSTRACT

Disclosed is a novel multilayered body for photolitho-graphic patterning of a photoresist layer from which a patterned resist layer having an excellent cross sectional profile can be obtained when the multilayered structure comprises, on the surface of a substrate, an underlying water-insoluble anti-reflection film and a negative-working photoresist layer of a specific photoresist composition comprising:  
     (A) 100 parts by weight of an alkali-soluble resin;  
     (B) from 0.5 to 20 parts by weight of an onium salt compound capable of releasing an acid by irradiation with actinic rays; and  
     (C) from 3 to 50 parts by weight of a glycoluril compound substituted by at least one hydroxyalkyl group or alkoxyalkyl group at the N-position.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a multilayered body forphotolithographic patterning or, more particularly, to a multilayeredbody for photolithographic patterning of a resist layer comprising asubstrate, a first anti-reflection coating film formed on the surface ofthe substrate, a layer of a specific negative-working photoresistcomposition on the first anti-reflection coating film and, optionally, asecond anti-reflection coating film formed on the resist layer andsuitable for obtaining, with high photosensitivity, a patterned resistlayer of high pattern resolution having excellently orthogonal crosssectional profile with little edge roughness.

[0002] Along with the trend in recent years toward higher and higherdegree of integration in various semiconductor devices, thephotolithographically patterned resist layer on a substrate surface isrequired to have a pattern resolution of as fine as 250 nm or, as atarget in the coming generation, as fine as 200 nm. Needless to say,such an extremely fine pattern resolution of the patterned resist layercannot be accomplished without an innovative improvement in theperformance of the photosensitive patterning material which may be aphotosensitive material for patterning of a chemical-amplificationnegative-working photoresist layer.

[0003] The above mentioned chemical-amplification negative-workingphotoresist composition is typically formulated with an acid-curablealkali-soluble resin such as a phenolic resin, a radiation-sensitiveacid-generating agent and a crosslinking agent for the resin such as anaddition product of urea or melamine and formaldehyde. It is usual thata photoresist layer of a chemical-amplification negative-workingphotoresist composition is formed not directly on the surface of asubstrate but on an undercoating layer of an anti-reflection film of awater-insoluble anti-reflection compound formed on the substrate surfacein view of the advantage relative to the pattern resolution which can beas fine as 200 nm or even finer.

[0004] It is sometimes the case, however, that, when a conventionalchemical-amplification negative-working photoresist composition is usedin combination with an anti-reflection coating film including organicfilms formed from the most typical commercial products of the DUV Series(each a product by Brewer Science Co.) as well as inorganicanti-reflection coating films, an excellently orthogonal cross sectionalprofile of the patterned resist layer can hardly be obtained and thecross sectional profile is more or less trapezoidal or skirt trailing.Accordingly, it is one of the target problems in the development worksfor negative-working photoresist compositions to obtain achemical-amplification negative-working photoresist composition capableof being used in combination with an anti-reflection coating filmwithout being influenced in the pattern resolution and cross sectionalprofile of the patterned resist layer.

[0005] It is sometimes the case that formation of a resist pattern isaccompanied by an undesirable phenomenon of “edge roughness”,especially, when the resist pattern width is extremely fine to be 200 nmor smaller.

[0006] It is known according to the disclosure in Japanese Patent No.2878150, on the other hand, that, when a photo-resist layer of apositive-working or negative-working photoresist composition of thechemical-amplification type is provided thereon with an anti-reflectionfilm of a water-soluble anti-reflection compound, an improvement in thepattern resolution and suppression of the adverse influences of standingwaves can be accomplished.

[0007] Although it is a possible way that a substrate surface isprovided with three coating layers successively consisting of a firstanti-reflection film of a water-insoluble anti-reflection compound, aphotoresist layer and a second anti-reflection film of a water-solubleanti-reflection compound, the photolithographic patterning work by usingsuch a patterning material cannot be very efficient because both of thesteps for removal of the water-soluble anti-reflection film and etchingof the water-insoluble anti-reflection film. Accordingly, it is usual inthe manufacturing process of semiconductor devices in which a very highthroughput of the products is essential that the photolithographicpatterning material has a two-layered coating on the substrateconsisting either of a water-insoluble anti-reflection film and aphotoresist layer thereon or of a photoresist layer and a water-solubleanti-reflection film thereon.

[0008] A patterning material having a two-layered coating consisting ofa negative-working photoresist layer and a water-soluble anti-reflectionfilm thereon has a problem that an unnecessary crosslinking reactionproceeds at or in the vicinity of the interface between the two coatinglayers eventually resulting in a T-formed cross sectional profile of thepatterned resist layer. While it is eagerly desired to obtain apatterned resist layer having excellently orthogonal cross sectionalprofile, in addition, attention in the development works is now switchedto a patterning material of the three-layered coating from which apatterned resist layer having an excellently orthogonal cross sectionalprofile by overcoming the problems of a skirt trailing cross sectionalprofile at the interface between the water-insoluble anti-reflectioncoating film and the photoresist layer and a T-formed cross sectionalprofile at the interface between the photoresist layer and thewater-soluble anti-reflection film thereon.

SUMMARY OF THE INVENTION

[0009] The present invention accordingly has an object to provide anovel and improved multilayered body for photolitho-graphic patterningof a photoresist layer free from the above described problems anddisadvantages in the conventional multilayered body for resistpatterning.

[0010] Thus, the multilayered body for photolithographic patterning of aphotoresist layer provided by the present invention comprises, as anintegrally layered body:

[0011] (a) a substrate;

[0012] (b) an anti-reflection coating film formed on the surface of thesubstrate from a water-insoluble anti-reflection compound in a thicknessin the range from 30 to 300 nm; and

[0013] (c) a photoresist layer having a thickness in the range from 200to 500 nm formed on the anti-reflection coating film from anegative-working photoresist composition comprising

[0014] (A) 100 parts by weight of an alkali-soluble resin;

[0015] (B) from 0.5 to 20 parts by weight of an onium salt compoundcapable of releasing an acid by the irradiation with actinic rays; and

[0016] (C) from 3 to 50 parts by weight of a glycoluril compoundsubstituted at the N-positions by at least one crosslink-formingsubstituent group selected from hydroxyalkyl groups and alkoxyalkylgroups.

[0017] Though optional, the anti-reflection coating film (b) contains anacid.

[0018] It is further optional that the patterning material comprises (d)a second anti-reflection coating film formed on the photoresist layer(c) from a water-soluble anti-reflection compound which comprises awater-soluble resinous ingredient and a fluoroalkyl sulfonate compoundor fluoroalkyl carboxylate compound.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A variety of substrate plates can be used without particularlimitations depending on the intended applications. Typical examples ofapplicable substrate materials include semiconductor silicon wafers withor without an undercoating film of SiON, SiN, Si₃N₄, polycrystallinesilicon and TiN and glass plates having a coating film of a metal suchas tantalum and chromium.

[0020] In the next place, the anti-reflection film formed on one surfaceof the substrate is limited to a water-insoluble anti-reflection filmwhich may be inorganic or organic. An inorganic water-insolubleanti-reflection coating film is formed usually by the chemicalvapor-phase deposition (CVD) method of an inorganic material while anorganic water-insoluble anti-reflection coating film is formed usuallyby coating the substrate surface with a coating solution containing anorganic ultraviolet absorbing polymeric compound in an organic solventfollowed by drying and a heat treatment. The thus formed water-insolubleanti-reflection coating film usually has a thickness in the range from30 to 300 nm.

[0021] Several commercial products of an anti-reflection coatingsolution for an organic water-insoluble anti-reflection film areavailable including a product sold under the trade name of DUV-42 (aproduct by Brewer Science Co.).

[0022] It is sometimes the case that, when a patterned resist layer isformed by using a photolithographic patterning material prepared byforming a negative-working photoresist layer on a substrate surfacehaving a water-insoluble anti-reflection coating film, an undesirablephenomenon of skirt trailing is found in the cross sectional profile ofthe patterned resist layer at the interface with the anti-reflectioncoating film. The mechanism of this undesirable phenomenon is presumablythat an acid ingredient in the anti-reflection coating film infiltratesto the photoresist layer in the course of the post-exposure bakingtreatment of the patterning material. In this regard, the presentinvention provides a remarkable improvement of preventing the phenomenonof skirt trailing in the cross sectional profile of the patterned resistlayer even when the photoresist layer is formed on a water-insolubleanti-reflection coating film containing a relatively large amount of anacid ingredient.

[0023] It is further optional that an additional anti-reflection coatingfilm, which must be soluble in water, is formed on the photoresist layerin a thickness of 35 to 45 nm. The water-soluble anti-reflection coatingfilm formed as the topmost layer is effective for improving the patternresolution of the patterned resist layer and preventing the adverseinfluences of the standing waves in the pattern-wise exposure to actinicrays.

[0024] The water-soluble anti-reflection coating film is formed bycoating the surface of the photoresist layer with an aqueous coatingsolution containing a water-soluble resinous compound such as polyvinylpyrrolidone and polyvinyl alcohol and a fluorine-containing surfaceactive agent including perfluoroalkyl sulfonic acids, e.g.,perfluorooctyl and perfluorodecyl sulfonic acids, or perfluoroalkylcarboxylic acids, e.g., perfluoroheptanoic acid and perfluorooctanoicacid, in the form of an ammonium salt, tetramethylammonium hydroxidesalt or monoethanolamine salt.

[0025] The negative-working photoresist layer in the inventivepatterning material is formed by using a photoresist compositioncomprising (A) an alkali-soluble resinous compound, (B) aradiation-sensitive acid-generating compound which is an onium saltcompound and (C) a glycoluril compound substituted by at least onecrosslink-forming group selected from lower hydroxyalkyl groups andlower alkoxyalkyl groups at the N-positions as the essential ingredientswith optional admixture of (D) an aliphatic amine compound and/or (E) anacid compounds selected from carboxylic acids and phosphorus-containingoxoacids or esters thereof. A photoresist composition comprising thecomponents (A), (B) and (C) is disclosed, for example, in JapanesePatent Kokai 10-254135.

[0026] The use of this photoresist composition in a photolithographicpatterning material has been established as a result of the extensiveinvestigations undertaken by the inventors with an object to develop aphotosensitive patterning material of which the total thickness of anegative-working photoresist layer and a water-insoluble anti-reflectionfilm does not exceed 800 nm leading to an unexpected discovery that thisobject can well be accomplished by a negative-working photoresistcomposition of the above mentioned formulation.

[0027] The component (A) in the negative-working photoresist compositionis an alkali-soluble resinous compound which is not particularlylimitative and can be selected from a variety of alkali-soluble resinsconventionally used in chemical-amplification photoresist compositions.Examples of alkali-soluble resinous compound particularly preferablefrom the standpoint of obtaining a patterned resist layer havingexcellent photosensitivity, pattern resolution and cross sectionalprofile of the patterned resist layer include copolymeric resins havinga weight-average molecular weight of 2000 to 4000 and consisting of 60to 97% by moles of hydroxystyrene units and 40 to 3% by moles of styreneunits, copolymeric resins having a weight-average molecular weight of2000 to 4000 and consisting of 60 to 97% by moles of hydroxystyreneunits and 40 to 3% by moles of styrene units, of which from 5 to 30% ofthe hydroxyl groups in the hydroxy-styrene units are substituted byalkali-insoluble groups and polyhydroxystyrene resins having aweight-average molecular weight of 2000 to 4000, of which from 3 to 40%of the hydroxyl groups in the hydroxystyrene units are substituted byalkali-insoluble groups. More preferably, the alkali-soluble resin asthe component (A) is a copolymeric resin having a weight-averagemolecular weight of 2000 to 4000 and consisting of 60 to 97% by moles ofhydroxystyrene units and 40 to 3% by moles of styrene units whenexcellent orthogonality of the cross sectional profile of the patternedresist layer is essential.

[0028] The alkali-insoluble group mentioned above is a group which hasan effect to decrease the alkali-solubility of a basicallyalkali-soluble resin when the resin is substituted by such groups.Examples of the alkali-insoluble group suitable for the purpose includetertiary-alkoxycarbonyl groups such as tert-butoxycarbonyl group andtert-amyloxy-carbonyl group and lower alkyl groups having 1 to 4 carbonatoms such as methyl group, ethyl group, propyl group, isopropyl group,n-butyl group and isobutyl group, of which the lower alkyl group or, inparticular, isopropyl group is preferable in view of obtaining a goodpatterned resist layer under little influences by the ambientconditions.

[0029] The acid-generating agent as the component (B) in the photoresistcomposition is a compound capable of releasing an acid by decompositionunder irradiation with actinic rays. While a variety ofradiation-sensitive acid-generating compounds are known and used inchemical-amplification photoresist compositions, the component (B) inthe photoresist composition is a specific onium salt compound of whichthe anionic moiety is a fluoroalkyl sulfonate anion. Such an onium saltcompound is a known compound as disclosed in Japanese Patent Kokai54-95686, 62-229942 and 2-120366 and elsewhere.

[0030] It is taught in Japanese Patent Publication 8-3635 that apreferable acid-generating agent in a negative-working photoresistcomposition for pattern-wise exposure with a KrF excimer laser beam istris(2,3-dibromopropyl) isocyanurate because this compound has anadvantage of high transparency to the KrF excimer laser beams and highpattern resolution of the patterned resist layer obtained by using thiscompound as the acid-generating agent.

[0031] This compound, from which a halogenoacid is generated byirradiation with actinic rays, however, is not suitable for use in aphotoresist composition containing a glycoluril compound as acrosslinking agent because the effective photosensitivity of thephotoresist composition cannot be high enough as to be applicable to anactual production line of LSIs.

[0032] Besides the above named halogenoacid-generating compound,sulfonic acid-generating compounds, such as bis(cyclohexyl-sulfonyl)diazomethane, are also known and used as an acid-generating agent inchemical-amplification photoresist compositions. These compounds arealso not suitable for use in combination with a glycoluril compoundsubstituted at the N-atoms by crosslink-forming groups selected fromhydroxyalkyl groups and lower alkoxyalkyl groups because a patternedresist layer of high pattern resolution can hardly be obtained with aphotoresist composition formulated with these compounds as theacid-generating agent and crosslinking agent.

[0033] It is the unexpected discovery leading to the present inventionthat the above described various problems can be overcome by combining aspecific onium salt compound as the acid-generating agent and a specificglycoluril compound as the crosslinking agent in a negative-workingphotoresist composition to give a patterned resist layer of excellentproperties.

[0034] The anionic moiety of the onium salt compound as the component(B) is a fluoroalkyl sulfonate anion. The fluoro-alkyl group thereof canbe a partially fluorinated or fully fluorinated alkyl group. The numberof carbon atoms in the fluoroalkyl group is not particularly limitative.It is preferable, however, that the fluoroalkyl group is aperfluoroalkyl group having 1 to 10 carbon atoms because of the generaltrend that the acid strength of the fluoroalkyl sulfonic acid isincreased as the degree of fluorination of the fluoroalkyl group isincreased and the number of carbon atoms in the fluoroalkyl group isrelatively small not to exceed 10.

[0035] On the other hand, the cationic moiety as the counterpart of thefluoroalkyl sulfonate anion to form the onium salt compound as thecomponent (B) is not particularly limitative and can be selected fromconventional ones. Examples of suitable cations include diphenyliodoniumcations and triphenylsulfonium cations optionally substituted by one ormore of lower alkyl groups such as methyl, ethyl, propyl, n-butyl andtert-butyl groups, di(lower alkyl) monophenylsul-fonium cations, loweralkylcyclohexyl 2-oxocyclohexylsulfonium cations and the like.

[0036] Examples of particularly preferable cations includediphenyliodonium cations represented by the general formula

[0037] in which R¹ and R² are each a hydrogen atom, alkyl group having 1to 4 carbon atoms or alkoxy group having 1 or 2 carbon atoms, such asdiphenyliodonium and bis(4-tert-butylphenyl) iodonium cations,triphenylsulfonium cations represented by the general formula

[0038] in which R³, R⁴ and R⁵ are each a hydrogen atom, alkyl grouphaving 1 to 4 carbon atoms or alkoxy group having 1 or 2 carbon atoms,such as triphenylsulfonium, tris(4-methyl-phenyl) sulfonium andtris(4-methoxyphenyl)sulfonium cations, phenyl dialkylsulfonium cationsrepresented by the general formula

[0039] in which each R⁶ is an alkyl group having 1 to 4 carbon atoms,such as dimethylphenylsulfonium cations and alkyl cyclohexyl2-oxocyclohexyl sulfonium cations represented by the general formula

[0040] in which R⁶ has the same meaning as defined above, such as methylcyclohexyl 2-oxocyclohexylsulfonium cation.

[0041] The onium salt compounds particularly preferable as the component(B) in the photoresist composition are those formed from these cationsand trifluoromethane sulfonate or nona-fluorobutane sulfonate anion or,more preferably, those formed from the triphenylsulfonium cationexpressed by the above given general formula (II) and trifluoromethanesulfonate or nonafluorobutane sulfonate anion. These onium saltcompounds can be used either singly or as a combination of two kinds ormore.

[0042] The amount of the onium salt compound as the component (B) in thephotoresist composition is in the range from 0.5 to 20 parts by weightor, preferably, from 5 to 15 parts by weight per 100 parts by weight ofthe alkali-soluble resin as the component (A). When the amount of thecomponent (B) is too small, the photosensitivity of the photoresistcomposition cannot be high enough. When the amount of the component (B)is too large, on the other hand, the photoresist composition suffers adecrease in the focusing depth latitude or in the storage stability.

[0043] It is essential in the present invention that thenegative-working photoresist composition is formulated with acrosslinking agent as the component (C) which is a specific glycolurilcompound substituted by a hydroxyalkyl group and/or an alkoxyalkyl groupat the N-position or positions.

[0044] The activity of these glycoluril compounds for cross-linking isgenerally low as compared with alkoxymethylated melamine compounds andalkoxymethylated urea compounds conventionally used as a crosslinkingagent in negative-working photoresist compositions. The low crosslinkingactivity of the glycoluril compound is rather an advantageous factorwhen used in combination with an onium salt compound as theacid-generating agent in respect of the improvements of the defectivecross sectional profile of the patterned resist layer such as skirttrailing and edge roughness as well as the T-formed cross sectionalprofile when a water-soluble anti-reflection coating film is provided ontop of the photoresist layer.

[0045] The above mentioned N-substituted glycoluril compound can beprepared by the condensation reaction of glycoluril with formaldehyde toform a hydroxymethyl-substituted compound which can be further reactedwith a lower alcohol to give an alkoxymethyl-substituted glycolurilcompound.

[0046] Particular examples of the N-substituted glycoluril compoundsuitable as the component (C) in the photoresist composition includemono-, di-, tri- and tetra(hydroxymethyl) glycolurils, mono-, di-, tri-and tetra(methoxymethyl) glycolurils, mono-, di-, tri- andtetra(ethoxymethyl) glycolurils, mono-, di-, tri- andtetra(propoxymethyl) glycolurils and mono-, di-, tri- andtetra(butoxymethyl) glycolurils. Several commercial products of theseN-substituted glycoluril compounds which can be used as the component(C) in the photoresist composition are available on the market includingthose sold under a trade name of N2702 (each a product by Sanwa ChemicalCo.) in the forms of mostly the trimer or tetramer as well as in theform of a mixture of the monomer, dimer and trimer.

[0047] The amount of the glycoluril compound as the component (C) in thephotoresist composition is in the range from 3 to 50 parts by weight or,preferably, from 10 to 20 parts by weight per 100 parts by weight of thecomponent (A). When the amount of the component (C) is too small, thecrosslink formation of the resinous ingredient cannot proceed completelyresulting in poor properties of the patterned resist layer. When theamount of the component (C) is too large, the photoresist compositionsuffers a decrease in the storage stability or decrease in thephotosensitivity with eventual formation of a particulate matter in thesolution during storage.

[0048] In addition to the above described essential ingredients, i.e.components (A), (B) and (C), it is optional that the photoresistcomposition is admixed with an aliphatic lower-alkyl or -alkanol aminecompound as the component (D) and/or a carboxylic acid or an oxoacid ofphosphorus as well as an ester thereof as the component (E). Theseadditional ingredients are known and conventionally employed innegative-working chemical-amplification photoresist compositions in theprior art.

[0049] Examples of the above mentioned aliphatic amine compound as thecomponent (D) include tertiary amines such as trimethylamine,triethylamine, tripropylamine, tributylamine, tripentylamine,triethanolamine and tripropanolamine and secondary amines such asdipropylamine, dibutylamine, dipentylamine and dipropanolamine.

[0050] The amount of the component (D) in the photoresist composition,when added, is in the range from 0.01 to 1.0 part by weight per 100parts by weight of the component (A).

[0051] Examples of preferable carboxylic acids as the component (E) inthe photoresist composition include malonic acid, citric acid, malicacid, succinic acid, benzoic acid and salicylic acid.

[0052] Examples of the oxoacid of phosphorus or a ester thereof as theother class of the component (E) include phosphoric and phosphorousacids and esters thereof such as phosphoric acid, phosphorous acid,di(n-butyl) phosphate and diphenyl phosphate, phosphonic acid and estersthereof such as phosphonic acid, dimethyl phosphonate, di(n-butyl)phosphonate, phenyl phosphonate, diphenyl phosphonate and dibenzylphosphonate and phosphinic acid and esters thereof such as phosphinicacid and phenyl phosphinate.

[0053] The amount of the component (E) in the photoresist composition,when added, is in the range from 0.01 to 1.0 part by weight per 100parts by weight of the component (A).

[0054] It is optional that the photoresist composition is admixed withthe component (D) alone, component (E) alone or both of the components(D) and (E) in combination.

[0055] Various further additives can optionally be added to thephotoresist composition including, for example, surface active agentshaving effectiveness to improve the film-forming properties of thephotoresist composition in the formation of a photoresist layer.

[0056] The photoresist composition used in the present invention isprepared usually in the form of a uniform solution by dissolving theabove described essential ingredients and optional ingredients in anorganic solvent which is not particularly limitative provided that thesolubility of each ingredient therein is high enough. Examples ofsuitable organic solvents include ketones such as acetone, methyl ethylketone, cyclohexanone, methyl isoamyl ketone and 2-heptanone, polyhydricalcohols and derivatives thereof such as ethyleneglycol, ethyleneglycolmonoacetate, diethyleneglycol, diethyleneglycol monoacetate,propyleneglycol, propyleneglycol monoacetate, dipropyleneglycol anddipropyleneglycol monoacetate as well as monomethyl, monoethyl,monopropyl, monobutyl and monophenyl ethers thereof, cyclic ethers suchas dioxane and esters such as methyl lactate, ethyl lactate, methylacetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate,methyl methoxypropionate and ethyl ethoxypropionate. These organicsolvents can be used either singly or as a mixture of two kinds or more.It is preferable that the organic solvent is a mixture ofpropyleneglycol monomethyl ether and propyleneglycol monomethyl etheracetate in a mixing proportion of 50:50 to 80:20 by weight inconsideration of the good solubility behavior to the components (B) and(C).

[0057] The present invention provides a photosensitive patterningmaterial which is an integrally layered body comprising (a) a substrateplate, (b) a water-insoluble anti-reflection film formed on the surfaceof the substrate plate and (c) a photoresist layer formed on theanti-reflection film from the above described negative-workingphotoresist composition.

[0058] The water-insoluble anti-reflection coating film is formed on thesubstrate surface in a thickness in the range from 30 to 300 nm. Thisthickness of the water-insoluble anti-reflection film as well as thethickness of the photoresist layer formed thereon are each an importantfactor affecting the quality of the patterned resist layer relative tothe pattern resolution and orthogonality of the cross sectional profilethereof. In this regard, the photoresist layer formed from thephotoresist composition should have a thickness in the range from 200 to700 nm or, preferably, from 200 to 500 nm or, more preferably, from 200to 400 nm. When the thickness of the photoresist layer deviates out ofthe range, satisfactory quality of the patterned resist layer cannot beensured relative to the dimensional accuracy and orthogonality of thecross sectional profile to negate the advantages to be obtained by thecombined use of the specific components (B) and (C).

[0059] In the following, the present invention is described in moredetail by way of Examples. In the following description, the term of“parts” always refers to “parts by weight”.

EXAMPLE 1.

[0060] A negative-working photoresist solution was prepared bydissolving, in a solvent mixture of 700 parts of propyleneglycolmonomethyl ether and 300 parts of propyleneglycol monomethyl etheracetate:

[0061] 100 parts of a copolymeric resin having a weight-averagemolecular weight of 2500 and consisting of 80% by moles ofhydroxystyrene units and 20% by moles of styrene units as the component(A);

[0062] 3 parts of triphenylsulfonium trifluoromethane sulfonate as thecomponent (B);

[0063] 10 parts of tetramethoxymethyl glycoluril (N2702, a product bySanwa Chemical Co) as the component (C);

[0064] 0.2 part of tributylamine as the component (D);

[0065] 0.2 part of salicylic acid as the component (E); and

[0066] a fluorosilicone-based surface active agent (X-70-093, a productby Shin-Etsu Chemical Co.) in an amount of 700 ppm by weight based onthe total amount of the non-volatile ingredients, followed by filtrationof the solution through a membrane filter of 200 nm pore diameter.

[0067] Separately, a 6-inch semiconductor silicon wafer was coated onone surface with an organic anti-reflection coating solution (DUV-42,supra) followed by drying and a heat treatment at 180° C. for 60 secondsto form an anti-reflection coating film of 80 nm thickness.

[0068] The negative-working photoresist solution prepared above wasapplied onto the anti-reflection coating film on a spinner rotating at2500 rpm for 30 seconds followed by drying on a hot plate at 90° C. for60 seconds to give a photoresist layer having a thickness of 500 nm.

[0069] The thus formed photoresist layer was pattern-wise exposed to KrFexcimer laser beams on a minifying projection exposure machine (ModelFPA-3000EX3, manufactured by Canon Co.) followed by a post-exposurebaking (PEB) treatment at 110° C. for 60 seconds and then subjected to adevelopment treatment as a puddle development with a 2.38% by weightaqueous solution of tetramethylammonium hydroxide at 23° C. for 60seconds followed by rinse for 15 seconds in a running stream of purewater and drying to give a negatively patterned resist layer.

[0070] The critical resolution of the line-and-space patterned resistlayer was 180 nm. The cross sectional profile of the line-patternedresist layer of the critical resolution was excellently orthogonalstanding upright on the substrate surface without skirt trailing in thevicinity of the interface with the anti-reflection layer.

[0071] The minimum exposure dose for obtaining a patterned resist layerof 180 nm line width was 40 mJ/cm² which was taken as a measure of thephotosensitivity of the photoresist composition. The thus line-patternedresist layer was almost free from edge roughness.

EXAMPLE 2.

[0072] A negative-working photoresist solution was prepared in the sameformulation as in Example 1 except that the triphenylsulfoniumtrifluoromethane sulfonate was replaced with the same amount of dimethylphenyl sulfonium trifluoromethane sulfonate.

[0073] The same patterning procedure as in Example 1 was under-taken byusing the thus prepared photoresist solution to find that the criticalpattern resolution was for a line-and-space pattern of 180 nm line widthand the photosensitivity therefor was 50 mJ/cm². The cross sectionalprofile of the line-patterned resist layer was excellently orthogonalstanding upright on the substrate surface without skirt trailing in thevicinity of the interface with the anti-reflection film. The thusline-patterned resist layer was almost free from edge roughness.

EXAMPLE 3.

[0074] A negative-working photoresist solution was prepared in the sameformulation as in Example 1 except that the alkali-soluble resin as thecomponent (A) was replaced with the same amount of a polyhydroxystyreneresin having a weight-average molecular weight of 3000, of which 20% ofthe hydroxyl groups were substituted by isopropyl groups as analkali-insoluble group.

[0075] The same patterning procedure as in Example 1 was undertaken byusing the thus prepared photoresist composition to find that thecritical pattern resolution was for a line-and-space pattern of 180 nmline width and the photosensitivity therefor was 30 mJ/cm². The crosssectional profile of the line-patterned resist layer was excellentlyorthogonal standing upright on the substrate surface without skirttrailing in the vicinity of the interface with the anti-reflection film.The thus line-patterned resist layer was almost free from edgeroughness.

EXAMPLE 4.

[0076] A negative-working photoresist solution was prepared in the sameformulation as in Example 1 except that the tetra-methoxymethylatedglycoluril as the component (C) was replaced with the same amount oftetrabutoxymethylated glycoluril.

[0077] The same patterning procedure as in Example 1 was undertaken byusing the thus prepared photoresist composition to find that thecritical pattern resolution was for a line-and-space pattern of 180 nmline width and the photosensitivity therefor was 45 mJ/cm². The crosssectional profile of the line-patterned resist layer was excellentlyorthogonal standing upright on the substrate surface without skirttrailing in the vicinity of the interface with the anti-reflection film.The thus line-patterned resist layer was almost free from edgeroughness.

EXAMPLE 5.

[0078] The formulation of the negative working photoresist solution wasthe same as in Example 1 except that the solvent used here was a mixtureof 1050 parts of propyleneglycol monomethyl ether and 450 parts ofpropyleneglycol monomethyl ether acetate. The procedure for thepatterning test with the thus prepared photosensitive solution was alsothe same as in Example 1 except that the photoresist layer formed on theanti-reflection film had a thickness of 300 nm instead of 500 nm.

[0079] The results of the patterning test were that the critical patternresolution was 150 nm and the minimum exposure dose for obtaining aline-patterned resist layer of 150 nm was 40 mJ/cm². The cross sectionalprofile of the patterned resist layer was excellently orthogonalstanding upright on the substrate surface without skirt trailing in thevicinity of the interface with the anti-reflection film. The thusline-patterned resist layer was almost free from edge roughness.

EXAMPLE 6.

[0080] A negative-working photoresist solution was prepared in the sameformulation as in Example 5 except that the alkali-soluble resin as thecomponent (A) was replaced with the same amount of a polyhydroxystyreneresin having a weight-average molecular weight of 3000, of which 20% ofthe hydroxyl groups were substituted by isopropyl groups as analkali-insoluble group.

[0081] The same patterning procedure as in Example 5 was under-taken byusing the thus prepared photoresist solution to find that the criticalpattern resolution was for a line-and-space pattern of 150 nm line widthand the photosensitivity therefor was 35 mJ/cm². The cross sectionalprofile of the line-patterned resist layer was excellently orthogonalstanding upright on the substrate surface without skirt trailing in thevicinity of the interface with the anti-reflection film. The thusline-patterned resist layer was almost free from edge roughness.

EXAMPLE 7.

[0082] A negative-working photoresist solution was prepared in the sameformulation as in Example 5 except that the tetra-methoxymethylatedglycoluril as the component (C) was replaced with the same amount oftetrabutoxymethylated glycoluril.

[0083] The same patterning procedure as in Example 1 was undertaken byusing the thus prepared photoresist solution to find that the criticalpattern resolution was for a line-and-space pattern of 150 nm line widthand the photosensitivity therefor was 40 mJ/cm². The cross sectionalprofile of the line-patterned resist layer was excellently orthogonalstanding upright on the substrate surface without skirt trailing in thevicinity of the interface with the anti-reflection film. The thusline-patterned resist layer was almost free from edge roughness.

EXAMPLE 8.

[0084] A 6-inch semiconductor silicon wafer was provided on one surface,in the same manner as in Example 5, successively with an organicanti-reflection film of 80 nm thickness and a negative-workingphotoresist layer of 300 nm thickness with the same photoresistsolution.

[0085] The photoresist layer on the substrate surface was further coatedwith an anti-reflection coating solution of a water-soluble type(TSP-9AEX, a product by Tokyo Ohka Kogyo Co.) followed by drying to forma second anti-reflection film having a thickness of 42 nm, which waswater-soluble.

[0086] The same patterning test as in Example 5 was undertaken for theabove obtained photoresist layer sandwiched between two anti-reflectionfilms.

[0087] The critical pattern resolution was for a line-and-space patternof 150 nm line width and the photosensitivity therefor was 40 mJ/cm².The cross sectional profile of the line-patterned resist layer wasexcellently orthogonal standing upright on the substrate surface withoutskirt trailing in the vicinity of the interface with the water-insolubleorganic anti-reflection film and also without T-formed broadening at thetop portion which had been in contact with the water-solubleanti-reflection coating film. The thus line-patterned resist layer wasalmost free from edge roughness.

EXAMPLE 9.

[0088] A 6-inch semiconductor silicon wafer was provided on one surface,in the same manner as in Example 1, successively with a water-insolubleorganic anti-reflection film of 80 nm thickness and a negative-workingphotoresist layer of 500 nm thickness with the same photoresistsolution.

[0089] The photoresist layer on the anti-reflection film was furthercoated with an anti-reflection coating solution of a water-soluble type(TSP-9AEX, supra) followed by drying to form a second anti-reflectionfilm having a thickness of 42 nm, which was water-soluble.

[0090] The same patterning test as in Example 1 was undertaken for theabove obtained photoresist layer sandwiched between two anti-reflectionfilms.

[0091] The critical pattern resolution was for a line-and-space patternof 180 nm line width and the photosensitivity therefor was 40 mJ/cm².The cross sectional profile of the line-patterned resist layer wasexcellently orthogonal standing upright on the substrate surface withoutskirt trailing in the vicinity of the interface with the anti-reflectionfilm and also without T-formed broadening at the top portion which hadbeen in contact with the water-soluble anti-reflection coating film. Thethus line-patterned resist layer was almost free from edge roughness.

COMPARATIVE EXAMPLE 1.

[0092] The formulation of the negative-working photoresist solution wasthe same as in Example 1 except that the components (B) and (C) werereplaced with 5 parts of tris(2,3-dibromopropyl) isocyanurate and 10parts of methoxymethylated urea (MX-290, a product by Sanwa ChemicalCo.), respectively.

[0093] A patterning test was undertaken in the same manner as in Example1 by using the above prepared photoresist solution to obtain the resultsthat the critical pattern resolution was for a line-and-space pattern of200 nm line width and the photosensitivity therefor was 100 mJ/cm². Thecross sectional profile of the patterned resist layer had trailingskirts at the interface with the anti-reflection coating film below.

COMPARATIVE EXAMPLE 2.

[0094] The formulation of the negative-working photoresist solution wasthe same as in Example 1 except that the component (B) was replaced with5 parts of tris(2,3-dibromo-propyl) isocyanurate.

[0095] A test patterning procedure was undertaken in the same manner asin Example 1 with the thus prepared photoresist solution but failed togive a patterned resist layer.

COMPARATIVE EXAMPLE 3.

[0096] The formulation of the negative-working photoresist solution wasthe same as in Example 1 except that the component (B) was replaced with5 parts of bis(cyclohexylsulfonyl) diazomethane.

[0097] A patterning test was undertaken in the same manner as in Example1 by using the above prepared photoresist solution to obtain the resultsthat the critical pattern resolution was for a line-and-space pattern of300 nm line width and the photosensitivity therefor was 50 mJ/cm². Thecross sectional profile of the patterned resist layer had trailingskirts in the vicinity of the interface with the anti-reflection coatingfilm below.

What is claimed is:
 1. A multilayered body for photolithographicpatterning of a photoresist layer which comprises, as an integrallylayered body: (a) a substrate; (b) a water-insoluble anti-reflectionfilm formed on the surface of the substrate in a thickness in the rangefrom 30 to 300 nm; and (c) a photoresist layer having a thickness in therange from 200 to 500 nm formed on the anti-reflection film from anegative-working photoresist composition comprising, as a uniformsolution in an organic solvent, (A) 100 parts by weight of analkali-soluble resin; (B) from 0.5 to 20 parts by weight of an oniumsalt compound capable of releasing an acid by irradiation with actinicrays; and (C) from 3 to 50 parts by weight of a glycoluril compoundsubstituted by at least one hydroxyalkyl group or alkoxyalkyl group atthe N-position.
 2. The multilayered body for photolithographicpatterning of a photoresist layer as claimed in claim 1 in which theanti-reflection coating film contains an acid.
 3. The multilayered bodyfor photolithographic patterning of a photoresist layer as claimed inclaim 1 which further comprises: (d) a water-soluble anti-reflectioncoating film formed on the photoresist layer.
 4. The multilayered bodyfor photolithographic patterning of a photoresist layer as claimed inclaim 3 in which the water-soluble anti-reflection coating filmcomprises a water-soluble resinous compound and a fluoroalkyl sulfonateor a fluoroalkyl carboxylate.
 5. The multilayered body forphotolithographic patterning of a photoresist layer as claimed in claim1 in which the negative-working photoresist composition furthercomprises: (D) from 0.01 to 1.0 part by weight of an aliphatic aminecompound per 100 parts by weight of the component (A).
 6. Themultilayered body for photolithographic patterning of a photoresistlayer as claimed in claim 1 in which the negative-working photoresistcomposition further comprises: (E) from 0.01 to 1.0 part by weight of acarboxylic acid, a phosphorus-containing oxoacid or an ester of aphosphorus-containing oxoacid per 100 parts by weight of the component(A).
 7. The multilayered body for photolithographic patterning of aphotoresist layer as claimed in claim 3 in which the water-solubleanti-reflection coating film has a thickness in the range from 35 to 45nm.